THE POSSIBLE NATURE OF QUASARS IN A COMPACT MODEL FOR THE UNIVERSE

The gravitational focusing of light rays in a compact model for the Un iverse is considered. In a compact space, light can return to its sour ce. Therefore, it is proposed that light rays emitted by a young, hot galaxy can return and be focused in the nuclear region of the galaxy, due to gravitational lensing by density inhomogeneities, such as clust ers of galaxies. The analysis takes into account changes in the freque ncy and flux density of the emitted radiation due to the cosmological expansion of space and to the gravitation of giant density inhomogenei ties (beats), which may consist of several superclusters of galaxies. It is shown that the energy flux of the returning radiation decreases more slowly than the Bur from a source in a uniform and isotropic mode l. Because of the expansion of space, the ultraviolet radiation of the galaxy at the epoch of the return of the radiation becomes infrared. Due to the focusing effect, the Bur of infrared photons is so large th at they rapidly heat the plasma in the galactic nucleus to relativisti c temperatures of the order of 10(12) K. Further heating results from induced Compton scattering on the electrons of the plasma. Compton sca ttering of the infrared emission on the hot electrons then transforms this emission into optical, ultraviolet, and X-ray radiation. As a res ult, a ''Compton reactor'' forms in the nucleus of the galaxy. In this region, the processes of heating of the plasma by incident infrared r adiation and cooling of the plasma by the transformation of the incide nt infrared radiation into higher-frequency radiation by hot electrons are dynamically balanced. The luminosity of the reactor is two to thr ee orders of magnitude lower than the luminosity of the young galaxy. The radiation of the reactor has a characteristic power-law spectrum. Its properties as a bright, variable nucleus resemble those of quasars or the nuclei of active galaxies.